Possible Heater Short in '90 C1500

[csennett0503]

Hey fellas,
So I just got this truck over the weekend and driving home the heat works fine, but I went to turn up the speed of the heat and it just cuts off, display and all. But not the radio. So I thought it popped a fuse, the fuse is fine. The only thing that happens now is a weird "click, click, click..etc" once in a while that the only way to stop it is to restart the truck.
Any pointers?
Thanks!

 

[Keepinitoldskool]

Sounds like a bad relay or blower resistor

 

[csennett0503]

How would I go about checking that out